Method and apparatus for aspiration

ABSTRACT

An aspiration apparatus is described that includes a guide and a set of needles. The guide preferably has an approximately conical shape with a decreasing diameter in the distal direction. A plurality of lumens extend between a distal end portion and a proximal end portion of the guide. The needles have a tubular wall and are slidingly positionable in the lumens. The needles include a longitudinal section of the tubular wall that has a plurality of apertures that decrease in size in the proximal direction. The apertures define an approximately conically shaped area of harvest. The aspiration apparatus can connect to an external source of reduced pressure through the guide or directly to each needle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 12/676,396filed on Mar. 4, 2010, initially filed as PCT/US2007019267 filed on Sep.4, 2007.

FIELD OF THE INVENTION

The present invention relates to aspiration apparatuses and morespecifically to an aspiration apparatus that includes a guide thatdirects one or more needles for aspiration.

BACKGROUND OF THE INVENTION

Bone marrow is often used in orthodpaedic procedures to augment fracturehealing. It is also an excellent source of mesenchymal stem cells(MSC's) and/or tissue progenitor cells (TPC's). These multi-potent cellshave broad applications in addition to orthopaedics and may be used inthe fields of cardiology, oncology and other areas. As new techniquesare being developed to use these cells and to culture them ex-vivo ithas become increasingly important to be able to procure large volumes ofhighly cellular marrow from the body.

At present, the pelvis is the source for almost all of the marrow thatis used for mesenchymal stem cells. Obtaining marrow from the pelvis,however, can be difficult and may present risks to the abdominal cavity,especially when obesity obscures normal landmarks. Additionally,patients undergoing lower extremity procedures such as ankle or tibiafractures often do not have the pelvis readily accessible for sterilebone marrow access.

A further problem is that the aspiration of more than approximately twoto four cubic centimeters of marrow in one area has been shown to resultin the subsequent withdrawal of local “venous blood” as opposed tomarrow and therefore significantly deceases the MSC/TPC count. Thisrequires the frequent removal and redirection of the needle and canfurther include the creation of one or more additional points of accessinto the bone in order to avoid overlapping areas that have already been“tapped out” of marrow. Further, each additional point of access intothe bone creates additional risks to the abdominal cavity.

An apparatus is needed for the harvesting of marrow from a bone that canbe fixed relative to a bony landmark and guide multiple needles throughthat single penetration in the bone to harvest an increased volume ofmarrow.

SUMMARY OF THE INVENTION

A guide for the directional orientation of aspirating needles isdescribed that comprises a body that has a distal end portion and aproximal end portion. The distal end portion and proximal end portiondefine a central longitudinal axis. A plurality of lumens is defined inthe body and each lumen has a distal opening in the distal end portionand a proximal opening in the proximal end portion. Each lumen of theplurality of lumens defines an axis that has an acute oblique anglerelative to the central longitudinal axis such that the axes of thelumens diverge from the central longitudinal axis as the axes of thelumens exit from the distal opening. A fastener is positioned proximalto the distal end portion on the body. The fastener is adapted to fixthe body in the bone of a patient for the harvesting of tissue throughthe distal openings of the lumens in the distal end portion of the body.

The body can include an interior chamber that is in fluid communicationwith the plurality of lumens. The body can also include a guide needlethat extends distally from the distal end portion of the body. The guideneedle is in fluid communication with the chamber. The body defines alumen that extends between the chamber and a port in the proximal endportion. The port includes a fluid tight connector.

The guide can further include a set of needles. The needles have distalend portions and proximal end portions. Each needle has a tubular wallthat defines a lumen. A longitudinal section of the tubular wallincludes a plurality of apertures that are in fluid communication withthe lumen. The size of the apertures in the tubular wall varies todefine a desired shape of an area of harvest surrounding thelongitudinal section.

The proximal openings of the lumens in the body include a seat and theproximal portion of the needles has a key. The needles have a firstposition wherein the needles are separate from the guide and a secondposition wherein the key of the needle is connected to the seat and thelongitudinal section of the needle is positioned distal to the distalopening of the lumen in the body. The tubular wall of each needledefines a lumen that has a proximal terminal end aperture in the tubularwall and when the needle is in the second position the proximal terminalend aperture is in fluid communication with the chamber.

The guide is adapted to couple with a source of reduced pressure. Thesource of reduced pressure can be coupled to the fluid tight connectorof the port in the proximal end portion. The source of reduced pressuredraws fluid through the apertures of the needles, the lumens of theneedles, into the chamber and through the proximal port of the body.

The proximal end portion of the needles includes a proximal opening ofthe lumen and the proximal opening includes a fluid tight connector. Theexternal source of reduced pressure can be connected to the proximalopening of each needle.

A needle for use in aspiration is described that comprises an elongatetubular needle that includes a distal end portion and a proximal endportion that define a longitudinal axis. The needle has a tubularsidewall and the distal end portion includes a distal tip. Alongitudinally aligned lumen is defined by the sidewall that has adistal terminal end in proximity to the distal tip and an opposedproximal aperture. The proximal aperture is adapted to be coupled with asource of reduced pressure.

A region of the sidewall extends between a distal end in proximity tothe distal tip and a proximal end proximal to the proximal aperture. Theregion includes a plurality of apertures and each aperture of theplurality of apertures defines an area in the sidewall that is in fluidcommunication with the lumen. The area of each aperture in the regiondecreases in proximal direction.

An approximately conically shaped harvest area is defined by theplurality of apertures in the region when the source of reduced pressureis applied to the lumen, the conically shaped harvest area having afirst distal volume that tapers to a reduced second proximal volume inproximity to a proximal end of the region. The lumen has a proximalterminal end that is in proximity to the proximal aperture and theproximal aperture is an aperture in the sidewall. The needle proximalend portion defines the proximal aperture.

A method of aspirating using an aspiration apparatus is describedcomprising the steps of providing an aspiration apparatus including aguide and a set of needles. The guide includes a distal end portion anda proximal end portion that define a central longitudinal axis. Aplurality of lumens defines a plurality of distal openings in the distalend portion of the body and a plurality of proximal openings in theproximal end portion of the body. The lumens having an acute obliqueangle relative to the central longitudinal axis such that the alignmentof the lumens diverges as it extends from the distal openings in theguide. The guide includes a fastener positioned proximal to the distalend portion that is adapted to fix the guide in the bone relative to thepatient and provide access through the one incision for the distal endportion of guide that includes a plurality of distal lumen openings.

The method includes making an incision into the tissue and bone of apatient, positioning a guide of the aspiration apparatus at leastpartially into the incision and fixing the guide in position in theincision with the distal end portion of the guide inside the bone of thepatient. Positioning a set of needles in a first position relative tothe guide. The needles in the second position have a longitudinalsection that extends from the distal opening of the lumen in the distalend portion of the guide to the distal end portion of the needle.

An external source of reduced pressure can be connected to theaspiration apparatus to draw marrow through the needles. Thelongitudinal section of the needles has an arrangement of apertures thatdecreases the spacing between the apertures in the distal direction. Theguide needle is approximately aligned with the longitudinal axis. Theaspirated fluid is collected in a chamber in the guide. The aspiratedfluid is drawn from the chamber through the body using the externalsource of reduced pressure that is connected to the port of the guide.The collecting of the aspirated fluid or tissue can also be donedirectly from the proximal end portion of each needle by an externalsource of reduced pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the drawings, wherein like numerals are used to refer tothe same or similar elements.

FIG. 1 is a front and top perspective view of an aspiration apparatusconstructed in accordance with the present disclosure that includes aguide, one needle of a set of needles is in a first position separatefrom the guide and one needle is in a second position seated in theguide;

FIG. 2 is a cross-sectional view of the guide of FIG. 1 taken alonglines 2-2 showing one needle of the set of needles in the secondposition;

FIG. 3 is a side view of one of the needles of the set of needles ofFIG. 1;

FIG. 4 is a cross-sectional view of the needle of FIG. 3 taken alonglines 4-4;

FIG. 5 is a front and top perspective view of a second embodiment of theaspiration apparatus of FIG. 1 constructed in accordance with thepresent disclosure that includes a guide, one needle of a set of needlesis shown in the second position seated in the guide;

FIG. 6 is a cross-sectional view of the guide of FIG. 5 taken alonglines 6-6 with the one needle of the set of needles seated in the secondposition in the guide;

FIG. 7 is a side view of the one needle of the set of needles of FIG. 5;

FIG. 8 is a cross-sectional view taken along lines 8-8 of the needle ofFIG. 7;

FIG. 9 is a distal perspective view of aspiration apparatus of FIG. 1with two needles of the set of needles in the second position showingthe area of harvest;

FIG. 10 is a side cross-sectional view taken along lines 10-10 of FIG. 1with two needles of the set of needles in the second position in theguide;

FIG. 11 is a side perspective view of the guide of FIG. 1 beingconnected to a hard outer cortical bone of a patient;

FIG. 12 is a close-up of the side perspective view of the guide of FIG.11 fixed to the hard outer cortical bone of the patient;

FIG. 13 is the side perspective view of the aspiration apparatus of FIG.1 showing the set of needles in the second position and a syringeconnected to the guide as an external source of reduced pressure for theaspirating of marrow; and

FIG. 14 is the side perspective of the aspiration apparatus of FIG. 1using the syringe to aspirate an area of harvest.

DETAILED DESCRIPTION

Referring initially to FIG. 1, an aspiration apparatus 10 includes aguide 12 that provides directional alignment for one or more needles 14of a set of needles. Guide 12 has a body 16 with a distal end portion 18and a proximal end portion 20. Body 16 preferably has an approximatelyconical shape. In this preferred embodiment, body 16 has a distal endportion 18 has a first diameter that is less than a second diameter ofproximal end portion 20. Distal end portion 18 and proximal end portion20 define a central longitudinal axis-X. Aspiration apparatus 10 canselectively further include the set of needles. In this preferredembodiment, the set of needles has two needles 14. As shown, aspirationapparatus 10 has one needle 14 in a first position that is unconnectedwith the set of needles and one needle 14 in a second position seated inguide 12 for operational use.

Distal end portion 18 has a terminal end 22 that connects to a guideneedle 24. Guide or guide needle 24 extends distally along the centrallongitudinal axis-X. Guide 12 includes a fastener 26 that is inproximity to and proximal of distal end portion 18. A cutting edge ispreferably defined on at least a portion of the outer side wall ofdistal end portion 18. Guide 12 can also includes one or more handles 27that are connected to body 16.

Proximal end portion 20 includes a port 28 for a first lumen 30. Port 28has a fluid tight connector such as a leer lock that can interface withstandard connectors of external medical devices. First lumen 30 ispreferably aligned with the central longitudinal axis-X. In thispreferred embodiment, guide 12 also includes two lumens 32 that extendbetween a distal port 34 in distal end portion 18 and a proximal port 36in proximal end portion 20. In this preferred embodiment, the two distalports 34 are arranged along radii of central longitudinal axis-X thatare approximately ninety degrees apart. Similarly, proximal ports 36 arearranged along radii of central longitudinal axis-X that areapproximately ninety degrees apart. It is understood that the number andangular orientation of lumens 32 can vary depending upon the desiredapplication of aspiration apparatus 10.

Each lumen 32 slidingly receives a needle 14 from the set of needles 14.Proximal port 36 limits the longitudinal travel and fixes each needle 14in guide 12 in a second position of aspiration apparatus 10. In thispreferred embodiment the seat limits the distal longitudinal travel andcontrols the alignment of needles 14. In this preferred embodiment, thealignment of needles 14 includes an alignment device such as a slot 38that receives a key 39 of needles 14 and fixes the longitudinal traveland radial alignment of needles 14 in a predetermined direction. A fluidtight seal, such as a bias member, is provided between each lumen 32 andneedle 14.

Fastener 26 fixes the position and angular orientation of guide 12.Fastener 26 in this preferred embodiment is helical threads that engagethe patient's bone to fix the position and angle of guide 12 and isfabricated of one or more of metals, polymers or composite materialsthat have sufficient hardness to securely engage outer cortical bone.Fastener 26 can include alternative mechanical devices to fix theposition of guide 12 relative to the patient such as longitudinallyaligned grooves and/or a bias member.

As shown in FIG. 2, guide 12 defines an interior chamber 40 that is influid communication with first lumen 30 and second lumens 32. Guideneedle 24 has a tubular wall 42 that defines a lumen 44 that is in fluidcommunication with first lumen 30 of guide 12. Lumen 44 extends betweena distal end portion 46 and a proximal end portion 48 of needle 24.Distal end portion 46 of guide needle 24 includes a terminal end 50 thatis a solid point that is suitable for penetrating soft tissue. A firstportion of lumen 30 extends between proximal end portion 48 of guideneedle 24 and a rim 52 in the wall of chamber 40. A second portion oflumen 30 extends between a rim 54 in the wall of chamber 40 and port 28.Proximal end portion 48 of needle 24 is connected to distal end portion18 of guide 12.

Each lumen 32 is a through hole that is in fluid communication withchamber 40 and extends proximally from distal port 34 chamber 40 toproximal port 36. In this preferred embodiment, the first portion oflumen 32 extends from port 34 to a distal rim 56 in the wall of chamber40. A proximal rim 58 is defined in the wall of chamber 40 that extendsto proximal port 36. Each lumen 32 defines an axis-Y at an oblique acuteangle relative to central longitudinal axis-X. Lumens 32 preferablydefine straight through holes and axes, but lumens 32 can also bearcuate.

In this preferred embodiment, the angular relationship between axes-Y oflumens 32 is such that axes-Y diverge from each other and longitudinalaxis-X upon exiting from distal ports 34. It is understood that theangular relationship between axes-Y and the longitudinal axis-X can varydepending upon the particular application of guide 12. In the secondposition, needle 14 is fully inserted into and engaged with guide 12.

Referring now to FIGS. 2-4, each needle 14 has a distal end portion 64and a proximal end portion 66. Distal end portion 64 has a distal tip orterminal end 68 that is a solid point that is suitable for penetratingsoft tissue. Proximal end portion 66 includes a proximal end. Needle 14has a tubular wall 60 that defines a lumen 62.

Tubular walls or sidewalls 60 include a plurality of rims 70 that definea plurality of apertures 72. Rims 70 are arranged along a predefinedlongitudinal section 74 of needles 14 that extends proximally from aregion in proximity to distal end portion 64 for a predetermineddistance to an area distal to a proximal aperture 75. In this preferredembodiment, longitudinal section 74 extends between distal end portion64 and a region of needle 14 that extends distally from and is inproximity to distal port 34 of guide 12 when needle 14 is in the secondposition of aspiration apparatus 10.

Rims 70 formed in a tubular wall 60 define the size or area of apertures72 through tubular wall 60. The area defined by each rim 70 decreases inthe proximal direction from the distal end portion 64 such that the areadefined by rims 70 in proximity to the distal end portion 64 are greaterthan the area defined by rims 70 in proximity to the proximal end oflongitudinal section 74. The spacing between, angular orientation of andarrangement of rims 70 in tubular wall 60 can also vary along the lengthof longitudinal section 74.

Lumen 62 of needle 14 extends from a terminal end in proximity to soliddistal tip 68 to a solid wall in proximity to exit or proximal aperture75. When needle 14 is in the second position in guide 12, slot 38 alignswith key 39 of needle 14 to orient aperture 75 to face into chamber 40.The proximal terminal end or wall of lumen 62 preferably has an arcuateshape that redirects fluid flow through aperture 75 and into chamber 40.

Tubular wall 42 of guide needle 24 defines a plurality of rims 76 thatdefine a plurality of apertures 78. Rims 76 are arranged along apredefined longitudinal section 80 of needles 14. Longitudinal section80 extends along the longitudinal axis of needle 14 from a region inproximity to distal end portion 46 proximally for a predetermineddistance. In this preferred embodiment, longitudinal section 80 extendsbetween distal end portion 46 and a region in proximity to where needle24 connects to distal end portion 18 of guide 12. Rims 76 define thesize or area of apertures 78 through tubular wall 42. The area definedby each rim 76 decreases in the proximal direction from the distal endportion 44 such that the area defined by rims 76 in proximity to thedistal end portion 46 are greater than the area defined by rims 76 inproximity to the proximal end of longitudinal section 80. The density ofthe arrangement of rims 76 in tubular wall 42 can also vary along thelength of longitudinal section 80.

As shown in FIG. 3, longitudinal section 74 harvests an approximatelyconically shaped three-dimensional area or volume of bone marrow harvest82. The proximal portion of area of harvest 82 is reduced in theproximal regions of longitudinal section 74 by the reduced area orradius and controlled spacing or arrangement of apertures 72 thatreduces the fluid flow into lumens 62. This is advantageous because theproximal region longitudinal sections 74 and 80 is where needles 14 andneedle 24 are in close proximity and the reduced area and arrangement ofapertures 72 and 78 limits the undesirable over harvesting of marrow.Similarly, the distal portion of volume of harvest 82 is increased inthe distal regions of longitudinal sections 74 by the larger areas andarrangement of apertures 72 that increases the laminar flow into lumens62.

The creation of the three dimensional shape of volume of harvest 82takes into consideration factors such as the arrangement, alignment andthe proximally directed decrease in the areas of apertures 72 of needles14 and apertures 78 of guide needle 24. The desired rate of laminar flowfrom each of apertures 72 and 78 for a given period of time ispreferably systematically calculated using Poiseuille's Law for laminarflow of an incompressible fluid such as high viscosity bone marrow.

Referring again to FIGS. 2-4, the size of area and controlled spacing ofapertures 78 in longitudinal section 80 of guide needle 24 is preferablythe same as that described above for apertures 72 and longitudinalsection 74 of needles 14. The volume of harvest 82 of needle 24 can beincreased in the direction away from needles 14 by the increase in sizeand decrease in spacing between apertures 78. Similarly, the radialalignment provided by slot 38 and key 39 of needle 14 can also includeorienting apertures 72 with increased areas in an outward direction andaway from the central longitudinal axis-X and/or other needles.

Aspiration apparatus 10 provides a secure fluid tight path ofcommunication from apertures 72 and apertures 78 to port 28. Apertures72 and apertures 78 are in fluid communication with their respectivelumens 62 and lumen 44 of needles 14 and 24, respectively. Lumens 62terminate at proximal apertures 75 in chamber 40 and lumen 44 is alignedwith the first portion of lumen 30 that is in fluid communication withchamber 40. The second portion of lumen 30 provides fluid communicationbetween chamber 40 and port 28. The sealing interface between needles 14and lumens 32 limits any undesirable intrusion or loss of fluid.

As shown in FIGS. 5 and 6, a second embodiment of aspiration apparatus10 includes guide 12 that omits guide needle 24 and has at least onelumen 32. Set of needles 14 can also be included in aspiration apparatus10. In this preferred embodiment, guide 12 defines three lumens 32. Body16 has a taper and includes distal end portion 18, proximal end portion20, terminal end 22, fastener 26, cutting edge and defines a centrallongitudinal axis-X as described previously in the first embodiment.

Lumens 32 extend between distal ports 34 and proximal ports 36. Distalports 34 and proximal ports 36 are preferably arranged at approximately120 degree intervals around central longitudinal axis-X. Each proximalport 36 includes a seat that preferably limits the distal travel andfixes one of needles 14 in the second position. The seat can include adevice 38 such as a slot that receives key 39 and fixes the radialposition of needle 14 in a single direction. A needle 14 is shown in thesecond position with a proximal end portion 66 seated in proximal port36 and longitudinal section 74 extending distally from guide 12.

Referring now to FIGS. 6-8, needle 14 in this preferred embodiment has alumen 62 that extends between solid distal tip 68 and a proximalaperture 75 defined in proximal end portion 66. In this preferredembodiment of needle 14, aperture 75 is positioned in the proximal endand aligned with longitudinal axis-Y of needle 14. The size of area andcontrolled spacing of apertures 72 defined by rims 70 control thelaminar flow into needle 14 and volume of harvest 82 as describedpreviously. Slots 38 and keys 39 can similarly provide an advantageousdirectional orientation of increased and/or decreased areas andcontrolled spacing of apertures 72. In this preferred embodiment ofneedles 14, apertures 65 of proximal end portions 66 include a fluidtight connector such as a leer lock that can interface with standardconnectors of external medical devices.

Aspiration apparatus 10 in the second position with needles 14 seated inguide 12 provides a secure path of fluid communication through lumen 62.Apertures 72 are in fluid communication with each lumen 62 and proximalaperture 75. The sealing interface between needles 14 and lumens 32limits any undesirable intrusion or loss of fluid.

Guide 12 as well as needles 14 and 24 can be fabricated from anysuitable medical grade material to include metals, polymers andcomposite materials. Guide 12 and needles 14 and 24 can also befabricated of clear materials or include clear windows positioned atstrategic points in guide 12 to enhance the visibility of the aspirationprocess.

As shown in FIG. 9, aspiration apparatus 10 with needles 14 of the setof needles in the second position shows the preferred approximatelyindividual conical shapes 82 of each needle 14 and overall conical shapeof the combined harvest volume 83 of the set of needles and guide needle24. Harvest volume 82 is reduced in proximity to guide 12 and expandedin proximity to distal end portions 64 and 46. Factors such as the size,spacing, angular direction and arrangement of rims 70 and 76 can varythe harvest area 82 of each needle 14 and 24 to minimize the overlapand/or expand the harvest area 82 in select directions. For example, theharvest volume 82 relative to the distal end portions 64 and 46 ofneedles 14 and 24, respectively, can be relatively flat or approximatelyhemispherical depending upon the orientation, size and arrangement orrims 70 and 76. Further the combined effect of the volume of harvests 82can be a greater volume of harvest 83 for aspiration apparatus 10.

Referring now to FIG. 10, when port 28 is coupled to a source of reducedpressure, that force applied through apertures 72 and 78 of needles 14and 24, respectively, produces controlled volumes of harvest 82 and 83.A fluid tight connection is provided through lumens 32 of guide 12,lumens 62 and 44 of needles 14 and 24, respectively, directly intochamber 40 and through first lumen 30.

As shown in FIGS. 11 and 12, in operation guide 12 of aspirationapparatus 10 is initially positioned into a small incision made throughthe skin and outer cortical bone near the proximal tibia. Guide needle24, when present, and at least a portion of distal end portion 18 ofguide 12 is inserted through the incision. Guide 12 is then fastened tothe bone of the patient. In this preferred embodiment, guide 12 isrotated about the longitudinal axis so that the cutting edge on the sideof distal end portion 18 is used to fasten guide 12 using the initialincision by using handles 27 to rotate guide 12. The continued rotationof guide 12 securely engages fastener 26 with the outer cortical bone.In this preferred embodiment, fastener 26 is a series of helical threadshaving sufficient hardness to engage outer cortical bone. Fastener 26enables the user of aspiration apparatus 10 to fix guide 12 in a desiredposition and at a desired angle of rotation relative to the bone andapertures 34 are position inside the outer cortical bone.

Referring now to FIG. 13, guide 12 is fixedly connected to the tibia ofthe patient and set of needles 14 are placed in the second position inguide 12 such that needles 14 are fully inserted into their respectivelumens 32 and longitudinal sections 74 are positioned external to guide12 and in the marrow. The radial orientation of needles 14 is preferablyfixed in this preferred embodiment by inserting keys 39 of needles 14 inslots 38 of proximal end portion 20 of guide 12 (See FIG. 6). Slots 38provide a limit of travel through guide 12 and a preferred angularorientation for each needle 14.

An external source of reduced pressure 84 such as a syringe with a leurlock interface is secured to proximal port 28. The external source ofreduced pressure or syringe 84 in this preferred embodiment generates areduced pressure through guide 12 and needles 14 in the second positionand guide needle 24. This reduced or negative pressure draws marrowthrough apertures 72 of needles 14 and apertures 78 of needle 24 andinto their respective lumens 62 and 44. The marrow is drawn from lumens62 and 44 into chamber 40. The marrow from apertures 72 and 78 is thendrawn through the second portion of lumen 30 and proximal port 28 intosyringe 84.

As shown in FIG. 14, in order to facilitate the drawing of marrow inthis preferred embodiment, port 28 and the second portion of lumen 30are approximately aligned with the wall of chamber 40 to assist thedrawing of marrow from chamber 40 into lumen 30 and syringe 84.Similarly, the configuration of chamber 40 can facilitate the downwardtravel of marrow into the second portion of lumen 30 from needles 14and/or 24. The position and alignment of port 28 and second lumen 30 aswell as the size and shape of chamber 40 is a function of a particularapplication of aspiration apparatus 10.

The area of harvest 82 for aspiration apparatus 10 preferably has adistally increasing approximately conical shape. This overall conicalshape of area of harvest 82 is due to the arrangement, alignment anddistally increasing areas of apertures 72 and 78 in needles 14 and 24that produce distally increasing approximately conically shaped volumeof harvest 82 for each needle 14 and 24. The shape of the volume ofharvest 82 are a result of the controlled application of Poiseuille'sLaw to minimize the rate of drawing of marrow from the proximal portionsof longitudinal sections 74 and 80 and increase the rate of drawing ofmarrow in the distal portions of longitudinal sections 74 and 80. It isunderstood, however, the three dimensional shape of an area of harvest82 can be advantageously varied depending upon the intended applicationof aspiration apparatus 10.

When desired, aspiration apparatus is withdrawn from the patient bypreferably terminating the application of the external source ofpressure and withdrawing needles 14 from the second position to thefirst position. Guide 12 is removed from the initial incision. Theexternal source of reduced pressure is disconnected from aspirationapparatus 10.

In the preceding specification, the present disclosure has beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident, however, that various modifications, combinations andchanges may be made thereto without departing from the broader spiritand scope of the invention as set forth in the claims that follow. Forexample, it is understood that the angle of axes-Y relative to axis-Xfor lumens 32 can vary depending upon the intended application ofaspiration apparatus 10 (See FIG. 6). Similarly lumens 32 and needles 14can be arcuate and define a single rim in chamber 40. In addition,though the present invention is described in terms of a series ofembodiments, each embodiment of the present invention can combine one ormore novel features of the other embodiments. The specification anddrawings are accordingly to be regarded in an illustrative manner ratherthan a restrictive sense.

What is claimed is:
 1. A needle for aspiration that comprises: anelongate tubular needle that includes a distal end portion and aproximal end portion, the distal end portion and proximal end portiondefine a longitudinal axis, the needle has a tubular sidewall and thedistal end portion includes a solid distal tip; a lumen aligned with thelongitudinal axis, the lumen defined by the sidewall and includes adistal terminal end in proximity to the distal tip and an opposedproximal aperture, the proximal aperture adapted to be coupled with anexternal source of reduced pressure; a plurality of apertures defined inthe sidewall, each aperture of the plurality of apertures has a definedarea in the sidewall that is in fluid communication with the lumen; anarrangement of the plurality of apertures, each aperture of theplurality of apertures has a defined location in the sidewall and anangular orientation that defines the angular orientation of a harvestvolume for each aperture, the arrangement includes varying the spacingbetween the locations of the apertures, the spacing between the locationof each aperture of the plurality of apertures selectively expanded andreduced to adjust the flow rate of a portion of the plurality ofapertures in defined directions, the angle of each aperture varyingrelative to other apertures to minimize the overlap of flow betweenapertures, the arrangement and the spacing between the locations of theapertures of the plurality of apertures arranged to minimize harvestvolume overlap between the apertures.
 2. The needle for aspiration ofclaim 1, wherein the arrangement of the plurality of apertures furtherincludes varying the size of each aperture of the plurality of aperturesto selectively expand and reduce the flow rate of individual aperturesin defined directions.
 3. The needle for aspiration of claim 1, whereinthe needle is arcuate.
 4. The needle for aspiration of claim 1, whereinthe tip is suitable for penetrating soft tissue.
 5. The needle foraspiration of claim 1, wherein the needle includes a window thatprovides visibility into the lumen.
 6. The needle for aspiration ofclaim 1, wherein the needle includes an alignment device for the angulardirectional orientation of the needle.
 7. A needle for aspiration thatcomprises: an elongate tubular needle that includes a distal end portionand a proximal end portion, the distal end portion and proximal endportion define a longitudinal axis, the needle has a tubular sidewalland the distal end portion includes a solid distal tip; a lumen alignedwith the longitudinal axis, the lumen defined by the sidewall andincludes a distal terminal end in proximity to the distal tip and anopposed proximal aperture, the proximal aperture adapted to be coupledwith an external source of reduced pressure; a region of the sidewallthat extends between a distal end in proximity to the distal tip andextends proximally for a predetermined distance to a proximal end, theregion includes a plurality of apertures, each aperture of the pluralityof apertures defines an area in the sidewall that is in fluidcommunication with the lumen; and a harvest volume defined by theplurality of apertures in the region when the external source of reducedpressure is applied to the proximal aperture of the lumen for apredetermined period of time, the harvest volume defined by thearrangement of the plurality of apertures in the region, each apertureof the plurality of apertures has a location in the region and anangular orientation, the angular orientation of each aperture of theplurality of apertures aligned to minimize the overlapping between theharvest volume of each aperture, the spacing between the locations ofthe apertures and angular orientation of the plurality of aperturesvarying so as to selectively expand the harvest volumes of the aperturesand minimize the overlap of the harvest volume of each aperture, thealignment of each aperture of the plurality of apertures and spacingbetween each of the plurality of apertures defines a controlled rate ofharvesting for a predefined shape of harvest volume upon the applicationof the reduced pressure, the arrangement of the plurality of aperturesand the harvest volume adapted for the aspiration of bone marrow.
 8. Theneedle for aspiration of claim 7, wherein the arrangement of theplurality of apertures further includes varying the size of eachaperture of the plurality of apertures to selectively expand and reducethe flow rate of individual apertures in defined directions.
 9. Theneedle for aspiration of claim 7, wherein the needle is arcuate.
 10. Theneedle for aspiration of claim 7, wherein the tip is suitable forpenetrating soft tissues and fixing the position of the needle in thebone.
 11. The needle for aspiration of claim 7, wherein the needleincludes a window that provides visibility into the lumen.
 12. Theneedle for aspiration of claim 7, wherein the needle includes analignment device for the angular directional orientation of the needleand harvest volume of the plurality of apertures.
 13. A method ofaspirating using an aspiration needle comprising the steps of: providingan aspiration needle, the needle has a distal end portion that includesa solid distal tip and a proximal end portion, the needle has a tubularwall that defines a lumen in the needle, the needle and lumen alignedwith a central longitudinal axis, the lumen has a distal terminal end inproximity to the distal end portion and a proximal aperture, a pluralityof apertures defined in the tubular wall of the needle and the pluralityof apertures in fluid communication with the lumen, the plurality ofapertures defining an arrangement of the locations and angularorientations of the apertures in the tubular wall and the spacingbetween the locations of the apertures and angular orientation of theplurality of apertures varying so as to minimize the overlap andselectively expand the harvest volumes of the apertures; positioning theneedle into an incision into a bone of a patient for the application ofharvesting bone marrow from a location in a bone having a predefinedshape of bone marrow; placing the needle in position in the incision andinside the bone of the patient for the harvesting of a volume of bonemarrow; connecting an external source of reduced pressure to theproximal aperture of the lumen, aspirating fluid through the pluralityof apertures and into the lumen; and harvesting a volume of marrow fromthe position of the needle inside the bone at a predefined rate of flowthrough the plurality of apertures over a defined period of time, therate of flow for the period of time for the plurality of aperturesdefining a shape of the harvest volume, the shape of the harvest volumedetermined by the arrangement of the plurality of apertures thatincludes the location, spacing between each aperture of the plurality ofapertures, alignment of each aperture of the plurality of apertures anda rate of flow through of each aperture of the plurality of apertures,the shape of the harvest volume of each aperture minimizing theoverlapping of harvest volume of each aperture.
 14. The method of claim13 wherein the step of providing further includes the angularorientation of each aperture of the plurality of apertures having analignment that minimizes a harvest volume of each aperture overlappingthe harvest volume of another aperture.
 15. The method of aspirating ofclaim 13, wherein the step of providing further includes varying thesize of the apertures to define the shape of the harvest volume.
 16. Themethod of aspirating of claim 13, wherein the step of harvestingincludes harvesting the volume of marrow from a single fixed position ofthe needle.
 17. The method of aspirating of claim 13, wherein the stepof harvesting further includes terminating the aspirating from thepatient at the predetermined position in the bone at the end of thedefined period of time.
 18. The method of aspirating of claim 13,wherein the step of positioning includes aligning the direction of theneedle for the application of harvesting of the bone marrow in the bone.19. The method of aspirating of claim 13, wherein the step of harvestinga volume of marrow includes the shape of the harvest volume of theapertures depending upon the application of the needle in the predefinedshape of bone marrow.